Based out of Boulder, just scrapped United from my list. This flying RJs for 2-4 hrs and paying $100-$400 more is just not making any sense. I pick United if it is the cheapest and quickest, else other carriers. Mileage and status are not valid anymore, so I dont bother about that at all. (thanks to United for getting me out of my addiction)
These days Southwest makes more sense to me as I get mainline aircraft nonstop to most of my destinations. It does not require one to be an elite to get service on Southwest. So I just buy in advance and with the no change fees adjust the tickets as business requires.
For International, just go with the one with the shortest connection times at the lowest price in Economy. When good Business class fares come along (YYZ-CPT-JNB-YYZ), I just buy a bunch of them for future travel.
BTW can someone shed some light on why is DEN-YYZ so expensive on all carriers, plus slim award tickets too.